Constant-temperature incubator



FIG. 1 is a front view of constant-temperature incubator;

FIG. 2 is a rear view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a right-side view thereof;

FIG. 6 is a left-side view thereof; and,

FIG. 7 is a top, front and right-side perspective view thereof. 

The ornamental design for a constant-temperature incubator, as shown. 